1. Field of the Invention
This invention relates generally to belt grinding machines and more particularly is directed towards a new and improved apparatus for sharpening the blade edges of ice skates.
2. Description of the Prior Art
The conventional technique for sharpening ice skates is to use a standard grinding wheel and to move the blade edge across the face of the wheel. The skate is usually held with the blade in the same plane as the wheel so that the blade edge is tangential to the wheel. Using the wheel with a cylindrical peripheral surface, the blade will be ground flat. If it is desired to hollow grind the blade, as is commonly the case, it is necessary to first shape the periphery of the wheel to the desired radius using an appropriate tool. Insofar as different types of skates require different curvatures, a considerable amount of time is involved in changing from one radius of curvature to another and a good deal of the wheel is wasted in the process. Further, conventional skate sharpening equipment tends to produce non-uniform results and different operators using the same equipment often produce different results.
In U.S. Pat. No. 4,078,337 there is disclosed a belt grinding machine for sharpening ice skates wherein a relatively narrow abrasive endless belt is moved along one of several curved working faces of a platen while a skate blade is moved lengthwise with respect to the platen and belt. While the foregoing apparatus produces a very good edge to the blade it has been found that the belt tends to wear rather rapidly, particularly along the center line thereof where most of the grinding action takes place. This required frequent changing of the belts and some wastage of materials.
It is an object of the present invention to provide improvements in belt grinding machines.
Another object of this invention is to provide an improved skate sharpening apparatus characterized by substantially complete utilization of abrasive belts and reduced wear thereon.
A further object of this invention is to provide a skate sharpening apparatus adapted to produce a high quality cutting edge on the blades of ice skates by relatively unskilled operators.
Still a further object of this invention is to provide a skate sharpening apparatus having a platen which is movable to change the center of curvature on a blade being sharpened as well as being provided with a platen formed with different curvatures which may be indexed easily into working position.